This application claims the benefit of the Korean Application No. P2000-086745 filed on Dec. 30, 2000, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a display device, and more particularly, to a liquid crystal display (LCD) device and a method for manufacturing the same.
2. Discussion of the Related Art
With the advent of an information society of the 20th century, display devices obtaining low power consumption, high quality, miniaturization and portability have been required in various consumption patterns.
A TFT-LCD device, a flat panel display device including a plasma display panel (PDP) having a large size, can satisfy these requests, so that the TFT-LCD device has been attracted as a display device that can substitute for a related art CRT device.
Especially, the TFT-LCD device can obtain lightness in weight, high resolution, low power consumption, and portability. Furthermore, the TFT-LCD device does not generate electromagnetic waves having biological hazard, and can be used in the intelligent buildings of high technology all day.
However, the TFT-LCD device has problems such as high manufacturing cost, narrow viewing angle, low luminance and disadvantage for manufacturing large sized display device even though technology of the display device is considerably developed.
A related art LCD device will be described with reference to the accompanying drawings.
FIG. 1 is a plan view of the related art LCD device, and FIG. 2 is a sectional view showing a structure of the related art LCD device taken along line I-Ixe2x80x2 of FIG. 1.
In general, an LCD device includes a lower substrate, an upper substrate, and a liquid crystal layer. A thin film transistor (TFT) array region is formed in the lower substrate, a black matrix film and a color filter film are formed on the upper substrate, and the liquid crystal layer is formed between the lower and upper substrates.
As shown in FIG. 1 and FIG. 2, a plurality of gate lines 110 are formed on the lower substrate 101a at a constant distance, and a plurality of data lines 103 are formed in perpendicular to the plurality of gate lines to define pixel regions of matrix type. Then, a plurality of TFTs are formed at crossing points of the plurality of gate and data lines 110 and 103 in each pixel region, and a plurality of pixel electrodes 105 are formed in each pixel region.
At this time, the unit TFT includes a gate electrode and source/drain electrodes. The gate electrode of the TFT (not shown in FIG. 2) projects from the gate line 110 on the lower substrate 101a. Then, a gate insulating film 102 is formed on an entire surface of the lower substrate including the gate electrode and the gate line, and the data line 103 and the source/drain electrodes (not shown in FIG. 2) are formed on the gate insulating film 102. A passivation film 104 of a silicon nitride film is formed on the entire surface of the lower substrate including the data line 103 and the source/drain electrodes. At this time, the drain electrode is connected to the pixel electrode 105 through a contact hole formed in the passivation film 104 on the drain electrode.
A plurality of black matrix films 106 are patterned on the upper substrate 101b at a constant distance to prevent light from being incident on the plurality of data lines 103, the plurality of gate lines 110 and the TFTs on the lower substrate 101a. Then, R/G/B color filter films 107 are formed between the black matrix films 106 for displaying colors, and then an over coat film 108 is formed on the color filter films 107 to protect and planarize the color filter films 107. Then, a plurality of common electrodes 109 of ITO are formed on the over coat film 108.
The lower and upper substrates 101a and 101b are attached to each other with a constant distance, and liquid crystal is injected between the lower and upper substrates.
However, the related art LCD device and the method for manufacturing the same have the following problems.
The plurality of black matrix films are formed on portions of the upper substrate corresponding to the TFTs and the gate/data lines, and then the color filter films are formed on the black matrix films. At this time, to obtain low resistance on a transparent conductive film, contact areas between the transparent conductive film and the black matrix film are reduced. Accordingly, uniformity of common voltage on the upper substrate can be degraded.
Accordingly, the present invention is directed to an LCD device that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an LCD device and a method for manufacturing the same that can improve uniformity of common voltage by increasing contact areas between a black matrix film and a transparent conductive film.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, an LCD device includes first and second substrates facing to each other, a plurality of color filter films formed in each pixel region on the first substrate, a plurality of gate and data lines formed on the color filter films to cross one another to define the pixel regions, a plurality of TFTs formed at crossing points of the plurality of gate and data lines, a plurality of pixel electrodes formed in the pixel regions on the first substrate, a plurality of island shaped first black matrix films formed on portions of the second substrate corresponding to the TFTs, and a plurality of common electrodes formed on an entire surface of the second substrate including the first black matrix films.
Preferably, a plurality of second black matrix films are formed between portions of the second substrate corresponding to the plurality of gate/data lines and the plurality of common electrodes.
Preferably, the plurality of second black matrix films are connected to the plurality of first black matrix films.
Preferably, the plurality of second black matrix films are narrower than the gate lines or the data lines.
Preferably, the pixel electrodes are overlapped with the gate lines or the data lines.
Preferably, a plurality of third black matrix films are formed between the color filter films below the TFTs and the first substrate, and a plurality of fourth black matrix films are formed between the color filter films below the gate/data lines and the first substrate.
Preferably, the plurality of third black matrix films prevent light of a backlight from being incident on active layers of the TFTs.
Preferably, the plurality of fourth black matrix films are wider than the gate lines or the data lines.
Preferably, the plurality of pixel electrodes are overlapped with the plurality of fourth black matrix films.
Preferably, a liquid crystal layer is formed between the first and second substrates.
In an LCD device according to the second embodiment of the present invention, the LCD device includes first and second substrate facing to each other, a plurality of color filter films in each pixel region on the first substrate, a plurality of gate and data lines formed on the color filter films to cross one another to define the pixel regions, a plurality of TFTs at crossing points of the plurality of gate and data lines, a plurality of pixel electrodes formed in each pixel region of the first substrate, a plurality of island shaped first black matrix films on portions of the second substrate corresponding to the TFTs, a plurality of second black matrix films on portions of the second substrate corresponding to the gate and data lines, and a plurality of common electrodes formed on an entire surface of the second substrate including the first and second black matrix films.
Preferably, the second black matrix films are formed on any one of the gate lines or the data lines.
In another aspect of the present invention, an LCD device includes the steps of forming a plurality of color filter films in each pixel region on a first substrate, forming an over coat film on the plurality of color filter films, forming a plurality of data and gate lines on the over coat film to cross one another, forming a plurality of TFTs at crossing points of the plurality of gate and data lines, forming a passivation film on the gate/data lines and the TFTs, forming pixel electrodes in the pixel regions on the passivation film, forming first black matrix films on portions of the second substrate corresponding to the TFTs, and forming common electrodes on the second substrate including the first black matrix films.
Preferably, a plurality of second black matrix films are formed between the common electrodes and portions of the second substrate corresponding to the gate lines or the data lines.
Preferably, the plurality of second black matrix films are narrower than the gate lines or the data lines.
Preferably, the plurality of pixel electrodes are overlapped with the gate lines or the data lines.
Preferably, a plurality of third black matrix films are formed between the color filter films below the TFTs and the first substrate, and a plurality of fourth black matrix films are formed between the color filter films below the gate/data lines and the first substrate.
Preferably, the plurality of pixel electrodes are overlapped with the plurality of fourth black matrix films.
Preferably, a liquid crystal is injected between the first and second substrates.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.